Clean up Azure AD Workload ID docs

[mboersma]

/kind documentation

What this PR does / why we need it:

Updates the Azure AD Workload ID doc for better formatting and tighter grammar.

Which issue(s) this PR fixes:

Refs #4138

Special notes for your reviewer:

There are probably more substantial changes to be made here to make this an easier document to follow, but I wanted to start by fixing the obvious things, mostly Markdown formatting.

• cherry-pick candidate

TODOs:

• squashed commits
• includes documentation
• adds unit tests

Release note:

NONE

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 62.48%. Comparing base (d817ab3) to head (ca91421).
Report is 31 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4776   +/-   ##
=======================================
  Coverage   62.48%   62.48%           
=======================================
  Files         196      196           
  Lines       16188    16188           
=======================================
  Hits        10115    10115           
  Misses       5333     5333           
  Partials      740      740           

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[mboersma]

/hold

So I don't forget to squash after reviewing.

[mboersma]

/hold cancel

Squashed, awaiting further review.

[willie-yao]

Just had one more comment in case you missed it, otherwise lgtm! #4776 (comment)

[willie-yao]

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: a5e1d9e6e6136622812183821f2c46d956a4c655

[nojnhuh]

/lgtm
/approve

[nojnhuh]

Just noting here that this step won't be necessary after #4765 merges since that changes all the templates to use WorkloadIdentity by default. I don't see this causing any issues though even after that, but would be some easy cleanup.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: nojnhuh

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